tiny terror build, a little terrible

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by wall_of_sleep, Jan 30, 2012.

  1. wall_of_sleep

    wall_of_sleep Member

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    I have been working on tweaking a Hammond to tiny terror build for a few days. My work hasn't been a total bust, but the break-up is "papery" similar to driving a high fi amp.

    schematic http://r.clear.home.insightbb.com/OTT.pdf

    My build uses a 5U4 rectifier and cheap poly caps virtually throughout. I believe my voltages are appropriate. I adjusted the first coupling cap to .027 because of a lack of bass response. My layout is sketchy but workable and I can't get the tone cut to work for love or money.

    Any tips/tricks on making this little guy more manageable are appreciated.
     
  2. diagrammatiks

    diagrammatiks Member

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    did you follow that schematic exactly?
     
  3. wall_of_sleep

    wall_of_sleep Member

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    Very close. My caps are oriented correctly or non-polarized. I will cover the amp again thoroughly to remove inconsistencies.
     
  4. Hwoltage

    Hwoltage Member

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    Out of curiosity, and if it's easy to do, perhaps remove the one end of the .22 cap to the 68k resistor and replace the connection with a wire from the input jack to the 68k resistor.

    Is this cap usually on the Tiny Terror?

    It won't help your tone control, but it might beef up the sound quite a bit.
     
    Last edited: Jan 30, 2012
  5. CaptainJake

    CaptainJake Member

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    I think all current production Oranges have that cap on the input stage
     
  6. Hwoltage

    Hwoltage Member

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  7. donnyjaguar

    donnyjaguar Member

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    If I can be candid, this is a terrible circuit obviously put together by someone with only a smattering of ignorance in MI design.
     
  8. diagrammatiks

    diagrammatiks Member

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    oh good somebody else said it.
     
  9. Hwoltage

    Hwoltage Member

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    Christ it's not that bad... There are a few resistors that probably aren't needed, and the potentiometer strategy is a little odd but it should function just fine.

    No need to discourage the guy.
     
  10. donnyjaguar

    donnyjaguar Member

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    I'm not slamming the OP by any means. He/she states that they're using a different rectifier than the original "design".
     
  11. Hwoltage

    Hwoltage Member

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    What are your issues with the rectifier?

    It's way over-filtered and the resistor values aren't reasonable per the current draw of the pre-amp stages but other than that...?

    The fuse on the B+ is a good addition, but the cap across the diodes is probably not a good idea unless it's VERY sturdy.

    Thoughts?
     
  12. diagrammatiks

    diagrammatiks Member

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    It's just an issue with how closely he followed the schematic.

    I've played with that circuit a bunch and it really needs to be built just like that dual pots and all in order to work correctly.
     
  13. wall_of_sleep

    wall_of_sleep Member

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    I gave this build a pretty solid effort this afternoon. The power tubes were combined to one resistor as shown on the schematic. I resolved issues with one or both screen resistors.

    Long story short, the amp now sounds like an Orange (to my ears) however there is not as much volume as there should be.

    -supply voltages look good, and tube swapping did not cause any change
     
  14. wall_of_sleep

    wall_of_sleep Member

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    figured it out.. put in the wrong value screen resistors :puh

    Sounds great, thanks all.
     

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